The present boom of underground constructions as a means of improving traffic connections and quality of life implies the transformation of tunneling from an empirical art towards a rational engineering science. Mechanics, being a vanguard of engineering science, is also a main ingredient of rational tunneling. A rational assessment of rock properties, action of support, environmental impact of excavation are unthinkable without a proper mechanical analysis. The rational approach is a particular quest of young engineers who enter the profession of tunnelling but do not have the experience claimed by a limited number of specialists. Thus, a Eurosummerschool of Tunneling Mechanics is in accordance with the aim of the European Commission towards an improved human potential. The vivid interest of the many participants confirmed this quest. Of course, the mechanics of tunnelling is an envolving discipline and, thus, wide off the mark. However, the contributions in this book are to be considered as some step towards this aim.